Influence of Low-Frequency Ultrasound on the Disintegration of Coliform and Fecal Coliform Bacteria

Wastewater contains an abundance of pathogenic microorganisms, which, if they infiltrate into the environment, can cause many bacterial diseases. The lack of widespread use of the wastewater disinfection process raises more and more concerns about the sanitary quality of the wastewater leaving treatment plants. This article aimed to test the effectiveness of the ultrasonic disintegration process against coliform bacteria and fecal coliforms in the treated wastewater. The paper presents the research on the use of ultrasound with a frequency of 20 and 40 kHz, with a variable and constant operating mode of an ultrasonic cleaner. The obtained test results confirm the effectiveness of the applied method. In most of the analyzed cases, 25-minute sonication reduced the number of tested microorganisms by over 90% compared to the control sample. Ultrasonic disintegration can therefore be successfully used in municipal wastewater treatment plants. The use of ultrasound for disinfection can improve the sanitary safety of the wastewater discharged into water or soil.